Method of forming drills



C. P. WINEMAN Y Dec. 9, 1924. 1,518,722

METHOD oF FORMING DRILLS Filed Junev 13 1921 A 9 Il I f f' am f3 2723- 52mm/WWW (Mbo/awww Patented Dec. 9, 1924.

UNIT-ED STATES PATENT OFFICE- orrAiiaIiEs. r. WrrTIgMAn, on nnmnorr, .MI;fzrrrssau.Jr assiiefisniR.ro.I nnrnor'r 'rwrsfr nnILL COMPANY, OF.- DErRQIT. M-LGHIGAN. Gewonnen. 0E MICHIGAN.

METHOD QE rosales Darms- Applcation filed vJr'rune 13,` 13.251. `Serial Np. 477,027.

` Toallwohom it may concern.'

.Beit known that I., CHARLES P. WINE-MAN, a citizen of the United States of America, residing at Detroit, in the county of fayne and State of Michigan, have invented certain new and useful Improvements in Methods ofForming Drills, of which the following is a specifhation7 reference being had therein to the accompanying;.drawings. Y' The invention relates to the manufact-ure of drills and refers particularly to,l those made of high speed steel. It is an; object of the invention to form a drill with as'little structural distortion of the' blank` of which the drill is formedy as ,possible and also forniv a drill in such a manner as toy sare inaterial by .utilizingall .the stock the blank. Another .object is the forming of recesses 1n the' blank toassist in g the samel while a 'rotio-thereo iS beasurset t0 formelle drill shank. 'A further 'object is therounding.' ofA the borners of vthe ydrill yblank to facilitate the .passage ofthe same through the groove forming rolls. WVith these ob]ects in view, the invention resides in the novel features more fully hereinafter set forth.

1n the drawings:

Figure 1 is a perspective view of one of the die blocks for forming the drill and showing the blank in its first position;

Figure 2 is a cross section throughthe original drill blank;

Figure 3 is a cross sectionv through the drill blank on the line 3-3 0f Figure 1;

Figures 4 and 5 are side elevations of the die block showing the drill blank in its second position respectively before and after being operated upon;

Figures 6, 7 and 8 are cross sections through the drill blank respectively on lines 6 6, 7-7 and 8-8 of Figure 5;

Figure 9 is a side elevation of the die block showing the drill blank in its third position;

Figure l0 is a cross section through the drill blank on the line 10-10 of Figure 9;

Figure 11 is a side elevation of adrill blank after it has passed through the groove forming rolls.

1 is one of a pair of identical die blocks having in its inner side the open ended recess 2 with the shoulder 3 at its inner end, and the parallel grooves 4 and 5 with open ends.

The drill blank 6 is a bar formed of. high speed steel suflicient lengthb to, form several and has originally a'rectangular cross section as shown partiflzularly inFigure. 2. The thickness of this blank is substantially equal to the thickness ofthe segment of the 'tinted portion of the drillwhile the width of the blankis`- Substantially equal tothe width 'of thel fluted portion'. This blank is first inserted into the recess 2 with its end abutting against the shoulder3 and its shorter sides parallel to theinner face of the die block sowthat upon operation of the die blocks,y the endl' of the blank is upset so that it will have a cross section as shown in Figure 3 inv which the t-lriclniessv is increased and the transverse dimensions will be. Substantially @finalized- As shown in Figuresy 4 vand 5, the Segond POStQn ,of thejdrill blank is Within the groove l with 'the upset end *7 abutting a suitable limit .gausefSji This groove has the rounded portion 92u one @nld adapted t0. feceive thel upset end 7, the substantially rectangular portion 10 for receiving the remainder of the drill blank with its longer sides parallel to the inner face of the die block, and also the lug or projection 11 at the inner end of the rounded portion 9, so that upon the moving of the two die blocks together, the projections 11 will form recesses 12 in the opposite sides of the drill blank. After these die blocks have been brought together the upset end 7 of the drill blank is further upset by suitable meanswhich in the present instance is the member forming the limit gauge 8 so that the completed upset end of the drill blank as shown in Figure 6 is circular in cross section. Due to the fact that the steel of which the drill is formed is high speed steel, it is particularly desirable to forni the recesses in the drill blank to hold the same while it is being upset to forni the shank. It is obvious in this connection that a separate limit gauge and heading tool can be used instead of having the one member to effect both functions.

Figure 9 shows the drill blank in its third position in the die block in which position the shorter sides of the portion 13 of the drill blank which has not been operated upon, are positioned parallel to the inner face of the die block s0 that when the two die blocks are brought together, the corners of this portion Will be rounded S0 that the same Will have a cross section as shown in Figure 10. After the corners have been rounded, the bail of stock is severed by suitable means to predetermined length.

The drill blank is next passed through the groove forming rolls, the grooves formed in the drill blank registering with the recesses 12 and being sufficiently deep so that these recesses do not appear in the ,drill blank after it has passed through the drill forming rolls as shown in Figure 11.

What I claim as my invention is:

l. In the methodrofmaking a drill, the forming of a shoulder on a polygonal blank to hold the same from longitudinal movement, and the upsetting of a portion of the blank to one side of the shoulder to form the drill shank While the shoulder is holding the blank from longitudinal movement.

2. ln the method of making a drill, the formingrof a recess in the drill blank to assist in holding the same from longitudinal movement, the upsetting of a portion of the drill blank to form the shank for the drill, and the form rolling of another portion of the blank -to form the fluted portion of the drill.

3. In the method of making a drill, the forming` of recesses in opposite sides of a polygonal blank to assist in holding the blank from longitudinal movement, the upsetting of an end portion vof the blank to one side of the recesses to form a shank for the K drill, and the forming of grooves in another portion of the blank and registering with;

the recesses to form the fluted portion of the drill. v

4;. In the method of making a drill, the forming of recesses in opposite sides of a polygonal blank to assist in holding the same froml longitudinal movement, the upsetting of an end portion of the drill to one bar to increase the thickness thereof, the

forming of recesses inthe Wider sides of the rectangular bar adjacent to the upset end portion, the upsetting of the upset end portion to form a rounded shank forthe drill,

the rounding of the corners of another pori tion of the rectangular bar, the form rolling of said last-mentioned portionof the rectangular bar to form grooves in opposite sides thereof registering With the recesses,

and the severing of the rectangular bar toJ predetermined length.

6. In the method of making a drill, kthe forming of a recess. in the drill blank and the forming of a groove in a portion of the blank and registering With the recessy to form the fluted portion of the drill.

In testimony whereof I aix my signature. s

CHARLES P. WINEMAN. 

